In accordance with documents U.S. Pat. No. 4,989,626 to Takaki et al. and U.S. Pat. No. 5,101,848 to Kojima et al., a static freeze valve for a fluid has already been described and proposed which comprises:
an element of pipe designed to receive said fluid in the flow area of said pipe, the wall of which is thermally conductive; PA1 one and the same heat source consisting of a Peltier-effect thermoelectric element arranged on the underside of the element of pipe and generating, in a controlled and alternating manner, heat and cold; this heat source is placed in thermal contact, especially by heat exchange, with said element of pipe in order to pass alternately and in a controlled manner, depending on the operation of the thermoelectric element, from a cold state, in which the fluid is capable, by freezing, of sealing off the passage through said element of pipe, to a hot state, in which said fluid is liquefied, thereby freeing said passage. PA1 (a) said element of pipe is obtained from a material, especially a metallic material, which is mechanically strong and capable of dissipating heat within itself in a controlled manner by the Joule effect, in order to constitute a hot source directly within its mass; PA1 (b) a cold source, separate from said hot source, designed and controlled to generate only cold, remains alone on the outside of said element of pipe, in thermal contact, especially by heat exchange, with said element of pipe. PA1 the cold source constitutes, or is chosen as, an immobile or moving refrigeration reservoir which is relatively large compared to the amount of cold necessary for the valve to pass from the hot state to the cold state; PA1 and the heat dissipated by the Joule effect in the element of pipe is controlled at a relatively high value, at least equal to that necessary to annul or annihilate, temporarily and locally in the region of the valve, the cold transferred by the cold source toward the element of pipe, in addition to the heat necessary to make the valve pass from the cold state to the hot state.
According to this document, the thermal source is therefore transferred to the outside of the element of pipe that is to be controlled as a valve.
Moreover, in this case the hot and cold sources are coincident in one and the same thermal source, which thus constitutes a parasitic mass which has to be cooled and heated alternately before transferring, respectively, cold and heat toward said element of pipe.
Overall, such a valve exhibits a relatively high thermal inertia which makes it difficult to achieve relatively short response times in order to pass from the open state to the closed state, or back again, limiting or preventing its use as a substitute for a conventional valve, for example a valve of the electromechanical type.